[INLONG-320] Request for static web contents would get responses with no content

[dockerzhang]

After clearing the cache, refresh homepage of master would result in loss of static materials, like styles, scripts and pictures, while all dynamic elements are working as expected.
The looks would be like in attachments.

This should be due to Servlet binding on Embedded-Jetty, which does too much to cover Servlet requests while missing the ability to respond static css contents.
So obviously the fix plan is to recover this ability, restoring original and expected behavior when browsing webpages.

JIRA link - [INLONG-320] created by hystericalhell